The invention relates to routing and delivery sorting of mail articles in one or more sorting offices of a postal operator. In some countries, postal sorting offices allow the senders of bulk mail, i.e. clients of the postal operator, to apply to each mail article a bar code representative of a delivery address code obtained by encoding the postal address of the mail article, said address code indicating a postal delivery point for the mail article being known as the “client code”. In a postal sorting office, during the process of subjecting a large batch of such marked mail articles to routing and delivery sorting, each mail article can be processed on the basis of a machine reading the bar code on the mail article. This provides a major saving in time for the postal sorting office and gives the sender, the postal operator's client, the option of benefiting from reduced postage rates.
The address code or client code for a mail article is conventionally generated by the sender on the basis of a machine inputting an image of the postal address of the article, followed by applying optical character recognition (OCR) to the characters in the image as input in order to extract information relating to the postal address of the mail article, followed by automatic processing of the address information in order to generate the address code. This processing typically makes use of a file in which reference address information is put into correspondence with reference address codes supplied by the postal operator. It has been found that the senders of bulk mail do not always have up-to-date reference address information files matching the respective reference address codes. This results in the postal sorting office finding addressing errors in the mail articles. This situation is particularly expensive for a postal operator since an addressing error leads to the postal sorting office recovering the wrongly addressed mail article only after the routing and delivery sorting process has been performed, with the article then either being returned to the sender, or by default being processed manually while ignoring the address code as generated by the sender. That type of error can affect a non-negligible fraction (sometimes as much as 6% to 10%) of a batch of mail articles delivered to a postal sorting office by a sender.
Patent document U.S. Pat. No. 4,992,649 discloses a method of processing mail articles in which the postal operator generates a mail article identity number for each mail article to be processed. The identity numbers are applied to the corresponding mail articles in the form of machine-readable markings, and they are recorded in an electronic file in association with data giving the postal addresses of the mail articles, said data optionally being a digital image of the postal address of each mail article. Such marking of mail articles with mail article identity numbers makes it possible to eliminate the use of delay loops through which each mail passes while waiting for processing in an installation for video-encoding mail articles.
Patent document EP-0 424 728 discloses another method of processing mail articles in which the identity numbers of mail articles are generated by a postal operator and are applied to the corresponding mail articles, while also being recorded in an electronic file in association with the image of the postal address of the mail article. On the basis of that file which can be transmitted over a network from a routing sorting office to a delivery sorting office of the postal operator, it is possible for the routing postal sorting office to begin by computing routing sort codes corresponding to the mail articles listed in the file. On this basis of this file, a delivery sorting office calculates delivery sorting codes or address codes.
Patent document FR-2 646 364 discloses another method of processing mail articles in which the identity numbers of mail articles are generated by a postal operator and in which an electronic file containing these identity numbers in association with data giving the postal addresses of the mail articles is transmitted over a network from a routing postal sorting office to delivery postal sorting offices.
Having the postal operator generate the identity numbers of mail articles simplifies the video-encoding operations that need to be performed in order to recover from errors in encoding postal addresses on certain mail articles. However it does not make it possible to eliminate erroneous addressing of mail articles because the sender does not always have an up-to-date postal address base.